IJSEM is the standard place. You will receive expert review there. Articles there are automatically "validly published" for purposes of defniitive taxonomy as established by IUMS. It may have lower impact factor, but it would be my first choice. Presumably there will be follow on articles on why you find this organism interesting, which could sensibly go to some of these other journals. J. Bacteriol or Microbiology would be my second choices (though the first choices for follow on articles).